<template>
<div class="xtx-infinite-loading" ref="container">
    <div class="loading" v-if="loading">
        <span class="img"></span>
        <span class="text">正在加载...</span>
    </div>
    <div class="none" v-if="finished">
        <span class="img"></span>
        <span class="text">亲，没有更多了</span>
    </div>
</div>
</template>

  
<script>
import {
    ref
} from 'vue'
import {
    useIntersectionObserver
} from '@vueuse/core'
export default {
    // 上拉加载更多组件
    name: 'XtxInfiniteLoading',
    props: {
    loading: {
      type: Boolean,
      default: false
    },
    finished: {
      type: Boolean,
      default: false
    }
  },

  setup (props, { emit }) {
    // 监听是否进入可视区
    const container = ref(null)
    useIntersectionObserver(
      container,
      ([{ isIntersecting }], dom) => {
        if (isIntersecting) {
          if (props.loading === false && props.finished === false) {
            // 发射一个方法 到底啦 父组件进行数据获取
            emit('infinite')
          }
        }
      },
      {
        threshold: 0
      }
    )
    return { container }
  }
}
</script>

  
<style lang="less" scoped>
.xtx-infinite-loading {
    .loading {
        display: flex;
        align-items: center;
        justify-content: center;
        height: 200px;

        .img {
            width: 50px;
            height: 50px;
            background: url(../../assets/images/load.gif) no-repeat center / contain;
        }

        .text {
            color: #999;
            font-size: 16px;
        }
    }

    .none {
        display: flex;
        align-items: center;
        justify-content: center;
        height: 200px;

        .img {
            width: 200px;
            height: 134px;
            background: url(../../assets/images/none.png) no-repeat center / contain;
        }

        .text {
            color: #999;
            font-size: 16px;
        }
    }
}
</style>
